The cellular distribution and changes in CX3CL1/fractalkine and its receptor CX3CR1 protein levels in the trigeminal subnucleus caudalis (TSC) of rats with unilateral infraorbital nerve ligation (IONL) were investigated on postoperation days 1, 3, 7, and 14 (POD1, POD3, POD7, and POD14, respectively) and compared with those of sham-operated and naïve controls. Behavioral tests revealed a significant increase in tactile hypersensitivity bilaterally in the vibrissal pads of both sham- and IONL-operated animals from POD1 to POD7, with a trend towards normalization in sham controls at POD14. Image analysis revealed increased CX3CL1 immunofluorescence (IF) intensities bilaterally in the TSC neurons of both sham- and IONL-operated rats at all survival periods. Reactive astrocytes in the ipsilateral TSC also displayed CX3CL1-IF from POD3 to POD14. At POD1 and POD3, microglial cells showed high levels of CX3CR1-IF, which decreased by POD7 and POD14. Conversely, CX3CR1 was increased in TSC neurons and reactive astrocytes at POD7 and POD14, which coincided with high levels of CX3CL1-IF and ADAM17-IF. This indicates that CX3CL1/CX3CR1 may be involved in reciprocal signaling between TSC neurons and reactive astrocytes. The level of CatS-IF in microglial cells suggests that soluble CX3CL1 may be involved in neuron-microglial cell signaling at POD3 and POD7, while ADAM17 allows this release at all studied time points. These results indicate an extended CX3CL1/CX3CR1 signaling axis and its role in the crosstalk between TSC neurons and glial cells during the development of trigeminal neuropathic pain.

• Klíčová slova
• chemokine receptors, chemokines, image analysis, immunohistochemistry, microglial cells, neurons, reactive astroglia,
• MeSH
• astrocyty metabolismus   MeSH
• chemokin CX3CL1 * metabolismus   MeSH
• CX3C chemokinový receptor 1 * metabolismus   genetika   MeSH
• krysa rodu Rattus MeSH
• mikroglie metabolismus   MeSH
• neuralgie trigeminu metabolismus   patologie   MeSH
• neuralgie metabolismus   patologie   MeSH
• neurony metabolismus   MeSH
• potkani Sprague-Dawley MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemokin CX3CL1 * MeSH
• CX3C chemokinový receptor 1 * MeSH
• Cx3cl1 protein, rat MeSH Prohlížeč
• CX3CR1 protein, rat MeSH Prohlížeč

Cannabinoid receptor type 2 (CB2R) plays a critical role in nociception. In contrast to cannabinoid receptor type 1 ligands, CB2R agonists do not produce undesirable central nervous system effects and thus promise to treat neuropathic pain that is often resistant to medical therapy. In the study presented here, we evaluated the bilateral distribution of the CB2R protein and messenger RNA (mRNA) in rat dorsal root ganglia (DRG) after unilateral peripheral nerve injury using immunohistochemistry, western blot, and in situ hybridization analysis. Unilateral chronic constriction injury (CCI) of the sciatic nerve induced neuropathic pain behavior and bilateral elevation of both CB2R protein and mRNA in lumbar L4-L5 as well as cervical C7-C8 DRG when compared with naive animals. CB2R protein and mRNA were increased not only in DRG neurons but also in satellite glial cells. The fact that changes appear bilaterally and (albeit at a lower level) even in the remote cervical DRG can be related to propagation of neuroinflammation alongside the neuraxis and to the neuroprotective effects of CB2R.

• Klíčová slova
• remote neuroinflammation, satellite glial cells, unilateral nerve injury,
• MeSH
• chování zvířat MeSH
• krysa rodu Rattus MeSH
• messenger RNA genetika   metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• nervus ischiadicus zranění   MeSH
• neuralgie genetika   metabolismus   patologie   MeSH
• potkani Wistar MeSH
• receptor kanabinoidní CB2 genetika   metabolismus   MeSH
• regulace genové exprese * MeSH
• spinální ganglia metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• messenger RNA MeSH
• receptor kanabinoidní CB2 MeSH